Drucker later elaborated on the setting of objectives in Managing by Results and many have considered this to be his most important contribution to management thinking. He shifted the focus of management actions away from the inputs to the outputs. It was management by results rather than management by supervision.
(...) Management by Objectives can turn into management by targets and quotas, with workers spending more time chasing the numbers than doing the real work. (...) Drucker knew this. The measures had to measure what really mattered. What Drucker wanted was a workplace where workers were trusted to get on with the job without undue supervision, where they knew what was expected of them and were clear about how it would be measured and how they would be rewarded.